Introduction to the BizTalk ESB Toolkit

This documentation explains the architecture and contents of the Microsoft BizTalk ESB Toolkit. The documentation also demonstrates how to apply an Enterprise Service Bus (ESB) architecture pattern to develop enterprise applications that enable flexible, secure, and reusable services and rapid organization of existing services into new end-to-end business processes.

The term Enterprise Service Bus is widely used in the context of implementing an infrastructure for enabling Service-Oriented Architecture (SOA). However, real-world experience with the deployment of SOA solutions has demonstrated that an ESB is only one of many components required to build a comprehensive Service-Oriented Infrastructure (SOI). The term "ESB" has evolved in a number of directions—its definition varies with the interpretation of individual ESB and integration platform vendors and with the requirements of particular SOA initiatives.

Based on the experience Microsoft has gathered from many successful real-world SOI implementations, Microsoft considers an Enterprise Service Bus to be a collection of architectural patterns based on traditional Enterprise Application Integration (EAI), message-oriented middleware, Web services, .NET and Java interoperability, host system integration, and interoperability with service registries and asset repositories. Figure 1 illustrates the architecture of an Enterprise Service Bus.

Figure 1

A high-level representation of the connectivity provided by the Enterprise Service Bus architecture

There are many sources of information about ESB design, architecture, infrastructure, and implementation available from industry suppliers, system integrators, and independent sources.

IBM defines ESB as a system that "...enables a business to make use of a comprehensive, flexible, and consistent approach to integration while also reducing the complexity of the applications being integrated. Due to the complex and varying nature of business needs, ESB is an evolutional progression that unifies message oriented, event driven and service oriented approaches for integrating applications and service." IBM describes the advantages as "...greater reuse of IT assets by separating application logics and integration tasks, so you can reduce the number, size, and complexity of integration interfaces," and the ability to "...add or change services with minimal interruption to existing IT environment; reduce cost and risk involved as business changes and new opportunities arise." For more information, see WebSphere software on the IBM Web site.

Sonic Solutions provide a comprehensive examination of ESB, discussing the principle aspects, and the IT and business benefits. They describe the requirement for ESB: "To integrate old and new, service-oriented architecture (SOA) needs an infrastructure that can connect any IT resource, whatever its technology or wherever it is deployed." For more information, see Enterprise Service Bus (ESB) on the Sonic Solutions Web site.

TIBCO Software define ESB as "...a standards-based communication layer in a service- oriented architecture (SOA) that enables services to be used across multiple communication protocols [to] simplify service deployment and management, and promote service reuse in a heterogeneous environment." They suggest, in order to provide these capabilities, ESBs "...support both open standards and proprietary technologies, including Web services and UDDI-based registries to discover and publish services, Java Message Service (JMS) and other widely deployed messaging protocols, standards-based (XML) transformations, and basic message routing." For more information, see Enterprise Service Bus (ESB) on the TIBCO Web site.

In the description of his book, Enterprise Service Bus, author David Chappell states that "Rather than conform to the hub-and-spoke architecture of traditional enterprise application integration products, ESB provides a highly distributed approach to integration." He adds "...with unique capabilities that allow individual departments or business units to build out their integration projects in incremental, digestible chunks, maintaining their own local control and autonomy, while still being able to connect together each integration project into a larger, more global integration fabric, or grid." For more information, see Enterprise Service Bus by David Chappell:

This documentation, as a whole, introduces architects and developers to ESB architectural concepts as addressed by the BizTalk ESB Toolkit, describes the installation procedures, and explains the functionality of the ESB components through a set of commonly accepted ESB use cases.

This section provides an introduction to the BizTalk ESB Toolkit and includes the following topics: